By Alistair Smout and Michael Holden LONDON (Reuters) -Scotland’s First Minister Nicola Sturgeon announced plans on Tuesday for a second referendum to be held on Scottish independence in October next year, vowing to take legal action to ensure a vote if the British government tried to block it. Sturgeon spoke as the Scottish government, which is led by her pro-independence Scottish National Party, published a referendum bill outlining plans for the secession vote to take place on Oct. 19, 2023. She also said she would be writing to British Prime Minister Boris Johnson for permission to hold a …